Gun-barrel.



- riling or grooves, so that no rot-ation is imvwell known that the higher the force of the vIn fact, a smooth or u'nriiied bore is the ideal periment in this line I'produced a projectile tory to acertain degree; `but in the course of NrTnD STATES )VILLIAM F. COLE,

ATENT (3m-ICEA OF WAOO, TEXAS.'`

SPECIFICATION forming part of Letters atent N o. 694,833, dated March 4, 1902.

Application filed July 16. 1901.

To all whom t may con/cern.: Y Beit known that LWvILLIAM F. COLE, a citizen of the United States,`and a resident of Vaco, in the county of McLennan and State of Texas, have made certain new and useful Improvements in Firearms, of which the following is a specification. i i

Itis Well known to experts in gunnery that a flat trajectory depends mainly upon the explosive forceA of the charge, the weight and rapidity of rotation of the projectile, and the friction or resistance encountered by the latter in traversing the gun-bore., It is also charge andthe greater the pitch of the riling the more liable is the projectile, more especiallyin small firearms, to ride or cross the parted to it, and if,`to meet this condition, the pitch of the riding be reduced the rapidity of rotation is necessarily lessened and with a corresponding tendency to impairment of the trajectory. In brief,` the intimate relation of the explosive force to the twist of the riliing forbids increase of either beyond a certain limit. Besides this, increase of twist results directly in increase of friction.

one in this regard; Attempts have been made to secure the desired en d by use of a gun having asmooth and twisted bore. Thus in one case a gun was provided with a bore which wascylindrical at the breech, the remainder being elliptical, without twist, and the longer axis of the ellipse being horizontal throughout, with the purpose of scattering a shot charge. In another case a gun was provided with a smooth and elliptical bore twisted throughout .and the projectile was of corresponding shape. In the course of exspecially adapted for guns of the type indicated, the same being the subject of United States Patent No. 671,877. The result obtained by such invention has been satisfacextended and further experiments I have discovered that a far better result maybe attained in small arms, not merely in trajectory, but in economy or cost of production as well, by meansof a gun constructed as here- Serial No. 68,459. (No model.)

inafter described, and illustrated in accompanying drawings, in'whichn Figure 1 is a longitudinal section of a portion of small Iire'arm of the Lee type. Fig. 2 is a cross-section on line 2 2 of Fig. l. Fig. 3 is a cross-section on line 3 3 of Fig. 1. Fig. 4 is across-section on lineLl-tof Fig. 1. Fig. 5 is a cross-section on line 5 5 of Fig. l.

The bore of the gun-barrel A is distinguished by the following characteristics: It is enlarged and cylindrical in the breech proper, 1, (see Fig. 2,) also cylindrical in the reduced throat, which extends from 2 to 2, (see Fig. 1,) while the remainder 3 of the bore is from 2 to 2, Fig. l. T-he throat thus inter-venesthe breech proper, l, and the elliptical part 3 and merges graduallyinto the latter. The twist of said part 3'is greater than that ordinarily given to ried smallarms and is uniform throughout,as illustrated by the inclination of the dotted line 6 in Figs. 4 and 5. The projectile passes immediately from the cylindrical throat 2 2 into the elliptical bore 3, whereby it is compressed and transformed transversely correspondingly, it becoming elliptical in crosssection and receiving a uniform twist. Thus While the greater resistance andfriction of the usual riding is avoided the greater pitch or twist of the bore 3 imparts a Very rapid rotation to the projectile, which the form of the latter assists in maintaining after it hasleft the gun, with the result that a fiat trajectory or one of minimum curvature is obtained. The gun is thus practically a combination of the best features of two systemsthe cylindrical and elliptical. By it I am enabled to use fixed ammunition of the ordinary cylindrical kind,whether the projectiles be of soft metal or mantled, a powder charge of unusual amount and of the highest explosive quality compatible with safety to the gun may be employed; also, a projectile of unusual weight, if desired.

In brief, my invention secured the'following IOO advantages: The cartridgechamber proper being cylindrical is the simplest and strongest form which could be desired. The bore being smooth, it is the simplest and most durable, so that the life of the gun is increased. By use of the elliptical twisted bore the rotation or twist of the projectile can beincreased over guns of the usual type. As the projectile cannot ride or strip, as projectiles often do in the ordinary type of rifles under high pressure, the eectiveness of range and penetrationisincreased. The weightoftheprojectile and size of powder charge may beincreascd beyond that of the guns of the usual typesay to at least twenty per cent. for eachtherebysecuring higher velocity, greater penetration, and consequently greater range and effectiveness, a result which the form given to the projectile in traversing the bore promotes.

It will be seen that my combination of a cylindrical and elliptical bores or bore-sections, whereby the gun is adapted for the fixed ammunition in ordinary use, is rendered practicable by the union or blending of the two bores or bore-sections by means of the throat 2 2, where the elongated projectile rests when the cartridge is fully inserted. As before intimated, other inventors as Well as myself had previously considered it necessary to employ an elliptical projectile in an elliptical bore, which continued and perfected experiments have demonstrated to be unsatisfactory and impracticable chiefly owing to the difficulty of inserting the cartridge with a twisting or rotary movement to prevent jamming. The plan was also objectionable for economical reasons. Y

It is to be understood that my improvement is applicable to all variations of shells or powder-cases whether having a uniform diameter or a differential one,as shown in the drawings.

l. A barrel for small firearms, having a bore which is lsmooth throughout, and cylindrical in the breech and throat, whereby it is adapted for reception of an ordinary ballcartridge, and elliptical and uniformly twisted in the remaining or outer portion to receive the projectile and give a rotary motion thereto as shown and described.

2. A barrel for small firearms having a smooth bore which is enlarged in the breech, and cylindrical in both breech and throat, the remainder of the bore being elliptical and having a uniform twist as shown and for the purpose specified.

3. A barrel for small firearms having an enlarged cylindrical breech-bore adapted for a ball-cartridge, an elliptical and twisted smooth front bore to receive the projectile and give a rotary motion thereto, and an intervening portion or throat which is reduced and cylindrical and serves to blend or merge the cylindrical part with the elliptical one, whereby the gun is adapted for use of Xed ammunition of the ordinary cylindrical type, in the manner described.

WILLIAM F. COLE.

Witnesses:

AMos W. HART, SoLoN C. KEMON. 

